Pen-type drug injection device and electronic add-on monitoring module for monitoring and logging dose setting and administration

ABSTRACT

A supplemental device for attachment to an injection device. A supplemental device for attachment to an injection device, the supplemental device comprising: a housing; an electromechanical switch arrangement, the electromechanical switch arrangement comprising: a main body; and a switching member, the switching member having a protrusion arranged to protrude from the main body so as to contact a surface of the injection device while the supplemental device is attached to the injection device; and a biasing member configured to bias at least a part of the main body of the electromechanical switch arrangement against the injection device while the supplemental device is attached to the injection device.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. National Phase Application pursuant to35 U.S.C. § 371 of International Application No. PCT/EP2013/065958 filedJul. 30, 2013, which claims priority to European Patent Application No.12179179.2 filed Aug. 3, 2012. The entire disclosure contents of theseapplications are herewith incorporated by reference into the presentapplication.

FIELD OF INVENTION

The present invention relates to a supplemental device for attachment toan injection device.

BACKGROUND

A variety of diseases exists that require regular treatment by injectionof a medicament. Such injection can be performed by using injectiondevices, which are applied either by medical personnel or by patientsthemselves. As an example, type-1 and type-2 diabetes can be treated bypatients themselves by injection of insulin doses, for example once orseveral times per day. For instance, a pre-filled disposable insulin pencan be used as an injection device. Alternatively, a re-usable pen maybe used. A re-usable pen allows replacement of an empty medicamentcartridge by a new one. Either pen may come with a set of one-wayneedles that are replaced before each use. The insulin dose to beinjected can then for instance be manually selected at the insulin penby turning a dosage knob and observing the actual dose from a dosewindow or display of the insulin pen. The dose is then injected byinserting the needle into a suited skin portion and pressing aninjection button of the insulin pen. To be able to monitor insulininjection, for instance to prevent false handling of the insulin pen orto keep track of the doses already applied, it is desirable to measureinformation related to a condition and/or use of the injection device,such as for instance information on the injected insulin type and dose.In this respect, WO 2009/024562 discloses a medical device with a valuesensor. A Radio Frequency Identification (RFID) unit comprises a valuesensor such as a pressure sensor and is integrated with a liquidmedicament container to enable wireless pressure or other medicamentrelevant parameter value monitoring. The liquid medicament container iscoupled with a first housing part of the medical device, which firsthousing part may for instance constitute a pre-filled disposableinjection device. The RFID unit communicates wirelessly with a controlcircuit that is contained in a second housing part of the medical devicethat is releasably attached to the first housing part. The controlcircuit is adapted to process the values measured by the RFID unit, tocompare it with pre-defined values and to provide an alert to the userif the measured values fall outside normal operating conditions, and tocommunicate data relating to the measured values to an external devicefor further data processing.

The control circuit of the medical device described in WO 2009/024562can thus be used with a series of pre-filled disposable injectiondevices, but the requirement that the RFID unit with the value sensor iscontained in the medicament container of the pre-filled disposableinjection devices significantly increases the costs of the pre-filleddisposable injection device.

It has been described, for instance in WO 2011/117212 to provide asupplementary device comprising a mating unit for releasably attachingthe device to an injection device The device includes a camera and isconfigured to perform optical character recognition (OCR) on capturedimages visible through a dosage window of the injection pen, thereby todetermine a dose of medicament that has been dialled into the injectiondevice.

SUMMARY

A first aspect of the invention provides a supplemental device forattachment to an injection device, the supplemental device comprising:

-   -   a housing;    -   an electromechanical switch arrangement, the electromechanical        switch arrangement comprising:    -   a main body; and    -   a switching member, the switching member having a protrusion        arranged to protrude from the main body so as to contact a        surface of the injection device while the supplemental device is        attached to the injection device; and    -   a biasing member configured to bias at least a part of the main        body of the electromechanical switch arrangement against the        injection device while the supplemental device is attached to        the injection device.

The electromechanical switch arrangement may be disposed in a recess inthe housing.

The biasing member may comprise a torsion spring having a first endsecured to the housing of the supplemental device and a second endsecured to the main body of the electromechanical switch arrangement.

The electromechanical switch arrangement may further comprise aninternal biasing member configured to bias the switching member towardsa protruding position in which the protrusion extends beyond the mainbody of the electromechanical switch arrangement.

The part of the main body of the electromechanical switch arrangementwhich is biased against the injection device may house the switchingmember. The main body of the electromechanical switch arrangement maycomprise an aperture and the part of the main body which is biasedagainst the injection device may comprise the aperture.

The whole of the main body of the electromechanical switch arrangementmay be biased against the injection device.

The electromechanical switch arrangement may be configured to be biasedagainst a moveable surface of the injection device while thesupplemental device is attached to the injection device. The surface ofthe injection device may be corrugated. The corrugations may be definedby troughs and crests.

The switching member may be rotatably mounted within the main body.

The supplemental device may further comprise a processor arrangementconfigured to determine whether the electromechanical switch arrangementis open or closed.

The supplemental device may further comprise a dose dialled detectoroperable to detect a dose of medicament dialled into an attachedinjection device. The dose dialled detector may comprise an imagecapture device and an optical character recognition system.

A second aspect of the invention provides a system comprising asupplemental device according to the first aspect of the invention andan injection device.

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures show:

FIG. 1a : an exploded view of an injection device;

FIG. 1b shows a perspective view of some detail of the injection deviceof FIG. 1;

FIG. 2a : a schematic illustration of a supplementary device to bereleasably attached to the injection device of FIG. 1 according to anembodiment of the present invention;

FIG. 2b : a perspective view of a supplementary device to be releasablyattached to the injection device of FIG. 1 according to variousembodiments of the present invention;

FIG. 2c : a perspective view of a supplementary device to be releasablyattached to the injection device of FIG. 1 according to otherembodiments of the present invention;

FIGS. 3a and 3b : possible distributions of functions among devices whenusing a supplementary device (such as the supplementary devices of FIGS.2a, 2b and 2c ) together with an injection device;

FIG. 4: a schematic view of the supplementary device of FIG. 2a in astate where it is attached to the injection device of FIG. 1;

FIG. 5a : a flowchart of a method used in various embodiments;

FIG. 5b : a flowchart of a further method used in various embodiments;

FIG. 5c : a flowchart of a still further method used in variousembodiments;

FIG. 6: a schematic illustration of a tangible storage medium 60according to an embodiment of the present invention; and

FIG. 7: an information sequence chart that illustrates an informationflow between various devices according to embodiments of the invention;

FIG. 8: a state diagram and flowchart illustrating operation of thedevice of FIG. 2b according to aspects of the invention;

FIG. 9: a state diagram and flowchart illustrating operation of thedevice of FIG. 2c according to aspects of the invention;

FIG. 10: a lateral cross-section taken through the injection device witha supplemental device attached;

FIG. 11: an axial cross-section taken through the injection device witha supplemental device attached;

FIG. 12: a state diagram illustrating operation of the injection devicewith a supplemental device attached.

DETAILED DESCRIPTION

In the following, embodiments of the present invention will be describedwith reference to an insulin injection device. The present invention ishowever not limited to such application and may equally well be deployedwith injection devices that eject other medicaments, or with other typesof medical devices.

FIG. 1 is an exploded view of an injection device 1, which may forinstance represent Sanofi's Solostar® insulin injection pen.

The injection device 1 of FIG. 1 is a pre-filled, disposable injectionpen that comprises a housing 10 and contains an insulin container 14, towhich a needle 15 can be affixed. The needle is protected by an innerneedle cap 16 and an outer needle cap 17, which in turn can be coveredby a cap 18. An insulin dose to be ejected from injection device 1 canbe selected by turning the dosage knob 12, and the selected dose is thendisplayed via dosage window 13, for instance in multiples of so-calledInternational Units (IU), wherein one IU is the biological equivalent ofabout 45.5 micrograms of pure crystalline insulin (1/22 mg). An exampleof a selected dose displayed in dosage window 13 may for instance be 30IUs, as shown in FIG. 1. It should be noted that the selected dose mayequally well be displayed differently, for instance by means of anelectronic display.

Turning the dosage knob 12 causes a mechanical click sound to provideacoustical feedback to a user. The numbers displayed in dosage window 13are printed on a sleeve that is contained in housing 10 and mechanicallyinteracts with a piston in insulin container 14. When needle 15 is stuckinto a skin portion of a patient, and then injection button 11 ispushed, the insulin dose displayed in display window 13 will be ejectedfrom injection device 1. When the needle 15 of injection device 1remains for a certain time in the skin portion after the injectionbutton 11 is pushed, a high percentage of the dose is actually injectedinto the patient's body. Ejection of the insulin dose also causes amechanical click sound, which is however different from the soundsproduced when using dosage knob 12.

Injection device 1 may be used for several injection processes untileither insulin container 14 is empty or the expiration date of injectiondevice 1 (e.g. 28 days after the first use) is reached.

Furthermore, before using injection device 1 for the first time, it maybe necessary to perform a so-called “prime shot” to remove air frominsulin container 14 and needle 15, for instance by selecting two unitsof insulin and pressing injection button 11 while holding injectiondevice 1 with the needle 15 upwards.

For simplicity of presentation, in the following, it will be exemplarilyassumed that the ejected doses substantially correspond to the injecteddoses, so that, for instance when making a proposal for a dose to beinjected next, this dose equals the dose that has to ejected by theinjection device. Nevertheless, differences (e.g. losses) between theejected doses and the injected doses may of course be taken intoaccount.

FIG. 2a is a schematic illustration of an embodiment of a supplementarydevice 2 to be releasably attached to injection device 1 of FIG. 1.Supplementary device 2 comprises a housing 20 with a mating unitconfigured and embrace the housing 10 of injection device 1 of FIG. 1,so that supplementary device 2 sits tightly on housing 10 of injectiondevice 1, but is nevertheless removable from injection device 1, forinstance when injection device 1 is empty and has to be replaced. FIG.2a is highly schematic, and details of the physical arrangement aredescribed below with reference to FIG. 2 b.

Supplementary device 2 contains optical and acoustical sensors forgathering information from injection device 1. Information is displayedvia display unit 21 of supplementary device 2. The dosage window 13 ofinjection device 1 is obstructed by supplementary device 2 when attachedto injection device 1.

Supplementary device 2 further comprises three user input transducers,illustrated schematically as a button 22. These input transducers 22allow a user to turn on/off supplementary device 2, to trigger actions(for instance to cause establishment of a connection to or a pairingwith another device, and/or to trigger transmission of information fromsupplementary device 2 to another device), or to confirm something.

FIG. 2b is a schematic illustration of a second embodiment of asupplementary device 2 to be releasably attached to injection device 1of FIG. 1. Supplementary device 2 comprises a housing 20 with a matingunit configured and embrace the housing 10 of injection device 1 of FIG.1, so that supplementary device 2 sits tightly on housing 10 ofinjection device 1, but is nevertheless removable from injection device1.

Information is displayed via display unit 21 of supplementary device 2.The dosage window 13 of injection device 1 is obstructed bysupplementary device 2 when attached to injection device 1.

Supplementary device 2 further comprises three user input buttons orswitches. A first button 22 is a power on/off button, via which thesupplementary device 2 may for instance be turned on and off. A secondbutton 33 is a communications button. A third button 34 is a confirm orOK button. The buttons 22, 33, 34 may be any suitable form of mechanicalswitch. These input buttons 22 allow a user to turn on/off supplementarydevice 2, to trigger actions (for instance to cause establishment of aconnection to or a pairing with another device, and/or to triggertransmission of information from supplementary device 2 to anotherdevice), or to confirm something.

FIG. 2c is a schematic illustration of a third embodiment of asupplementary device 2 to be releasably attached to injection device 1of FIG. 1. Supplementary device 2 comprises a housing 20 with a matingunit configured and embrace the housing 10 of injection device 1 of FIG.1, so that supplementary device 2 sits tightly on housing 10 ofinjection device 1, but is nevertheless removable from injection device1.

Information is displayed via display unit 21 of the supplementary device2. The dosage window 13 of injection device 1 is obstructed bysupplementary device 2 when attached to injection device 1.

Supplementary device 2 further comprises a touch-sensitive inputtransducer 35. It also comprises a single user input button or switch22. The button 22 is a power on/off button, via which the supplementarydevice 2 may for instance be turned on and off. The touch sensitiveinput transducer 35 can be used to trigger actions (for instance tocause establishment of a connection to or a pairing with another device,and/or to trigger transmission of information from supplementary device2 to another device), or to confirm something.

FIGS. 3A and 3 b show possible distributions of functions among deviceswhen using a supplementary device (such as the supplementary devices ofFIGS. 2a and 2b ) together with an injection device.

In constellation 4 of FIG. 3a , the supplementary device 41 (such as thesupplementary devices of FIGS. 2a and 2b ) determines information frominjection device 40, and provides this information (e.g. type and/ordose of the medicament to be injected) to a blood glucose monitoringsystem 42 (e.g. via a wired or wireless connection).

Blood glucose monitoring system 42 (which may for instance be embodiedas desktop computer, personal digital assistant, mobile phone, tabletcomputer, notebook, netbook or ultrabook) keeps a record of theinjections a patient has received so far (based on the ejected doses,for instance by assuming that the ejected doses and the injected dosesare the same, or by determining the injected doses based on the ejecteddoses, for instance be assuming that a pre-defined percentage of theejected dose is not completely received by the patient). Blood glucosemonitoring system 42 may for instance propose a type and/or dose ofinsulin for the next injection for this patient. This proposal may bebased on information on one or more past injections received by thepatient, and on a current blood glucose level, that is measured by bloodglucose meter 43 and provided (e.g. via a wired or wireless connection)to blood glucose monitoring system 42. Therein, blood glucose meter 43may be embodied as a separate device that is configured to receive asmall blood probe (for instance on a carrier material) of a patient andto determine the blood glucose level of the patient based on this bloodprobe. Blood glucose meter 43 may however also be a device that is atleast temporarily implanted into the patient, for instance in thepatient's eye or beneath the skin.

FIG. 3b is a modified constellation 4′ where the blood glucose meter 43of FIG. 3a has been included into blood glucose monitoring system 42 ofFIG. 3a , thus yielding the modified blood glucose monitoring system 42′of FIG. 3b . The functionalities of injection device 40 andsupplementary device 41 of FIG. 3a are not affected by thismodification. Also the functionality of blood glucose monitoring system42 and blood glucose meter 43 combined into blood glucose monitoringsystem 42′ are basically unchanged, apart from the fact that both arenow comprised in the same device, so that external wired or wirelesscommunication between these devices is no longer necessary. However,communication between blood glucose monitoring system 42 and bloodglucose meter 43 takes place within system 42′.

FIG. 4 shows a schematic view of the supplementary device 2 of FIG. 2ain a state where it is attached to injection device 1 of FIG. 1.

With the housing 20 of supplementary device 2, a plurality of componentsare comprised. These are controlled by a processor 24, which may forinstance be a microprocessor, a Digital Signal Processor (DSP),Application Specific Integrated Circuit (ASIC), Field Programmable GateArray (FPGA) or the like. Processor 24 executes program code (e.g.software or firmware) stored in a program memory 240, and uses a mainmemory 241, for instance to store intermediate results. Main memory 241may also be used to store a logbook on performed ejections/injections.Program memory 240 may for instance be a Read-Only Memory (ROM), andmain memory may for instance be a Random Access Memory (RAM).

In embodiments such as those shown in FIG. 2b , processor 24 interactswith a first button 22, via which supplementary device 2 may forinstance be turned on and off. A second button 33 is a communicationsbutton. The second button may be used to trigger establishment of aconnection to another device, or to trigger a transmission ofinformation to another device. A third button 34 is a confirm or OKbutton. The third button 34 can be used to acknowledge informationpresented to a user of supplementary device 2.

In embodiments such as those shown in FIG. 2c , two of the buttons 33,34 may be omitted. Instead, one or more capacitive sensors or othertouch sensors are provided.

Processor 24 controls a display unit 21, which is presently embodied asa Liquid Crystal Display (LCD). Display unit 21 is used to displayinformation to a user of supplementary device 2, for instance on presentsettings of injection device 1, or on a next injection to be given.Display unit 21 may also be embodied as a touch-screen display, forinstance to receive user input.

Processor 24 also controls an optical sensor 25, embodied as an OpticalCharacter Recognition (OCR) reader, that is capable of capturing imagesof the dosage window 13, in which a currently selected dose is displayed(by means of numbers printed on the sleeve 19 contained in injectiondevice 1, which numbers are visible through the dosage window 13). OCRreader 25 is further capable of recognizing characters (e.g. numbers)from the captured image and to provide this information to processor 24.Alternatively, unit 25 in supplementary device 2 may only be an opticalsensor, e.g. a camera, for capturing images and providing information onthe captured images to processor 24. Then processor 24 is responsiblefor performing OCR on the captured images.

Processor 24 also controls light-sources such as light emitting diodes(LEDs) 29 to illuminate the dosage window 13, in which a currentlyselected dose is displayed. A diffuser may be used in front of thelight-sources, for instance a diffuser made from a piece of acrylicglass. Furthermore, the optical sensor may comprise a lens (e.g. anaspheric lens) leading to a magnification (e.g. a magnification of morethan 3:1).

Processor 24 further controls a photometer 26, that is configured todetermine an optical property of the housing 10 of injection device 1,for example a colour or a shading. The optical property may only bepresent in a specific portion of housing 10, for example a colour orcolour coding of sleeve 19 or of an insulin container comprised withininjection device 1, which colour or colour coding may for instance bevisible through a further window in housing 10 (and/or in sleeve 19).Information on this colour is then provided to processor 24, which maythen determine the type of injection device 1 or the type of insulincontained in injection device 1 (e.g. SoloStar Lantus with purple colourand SoloStar Apidra with blue colour). Alternatively, a camera unit maybe used instead of photometer 26, and an image of the housing, sleeve orinsulin container may then be provided to processor 24 to determine thecolour of the housing, sleeve or insulin container by means of imageprocessing. Further, one or more light sources may be provided toimprove reading of photometer 26. The light source may provide light ofa certain wavelength or spectrum to improve colour detection byphotometer 26. The light source may be arranged in such a way thatunwanted reflections, for example by dosage window 13, are avoided orreduced. In an example embodiment, instead of or in addition tophotometer 26, a camera unit may be deployed to detect a code (forinstance a bar code, which may for instance be a one- or two-dimensionalbar code) related to the injection device and/or the medicamentcontained therein. This code may for instance be located on the housing10 or on a medicament container contained in injection device 1, to namebut a few examples. This code may for instance indicate a type of theinjection device and/or the medicament, and/or further properties (forinstance a expiration date).

Processor 24 further controls (and/or receives signals from) an acousticsensor 27, which is configured to sense sounds produced by injectiondevice 1. Such sounds may for instance occur when a dose is dialled byturning dosage knob 12 and/or when a dose is ejected/injected bypressing injection button 11, and/or when a prime shot is performed.These actions are mechanically similar but nevertheless sounddifferently (this may also be the case for electronic sounds thatindicate these actions). Either the acoustic sensor 27 and/or processor24 may be configured to differentiate these different sounds, forinstance to be able to safely recognize that an injection has takenplace (rather than a prime shot only).

Processor 24 further controls an acoustical signal generator 23, whichis configured to produce acoustical signals that may for instance berelated to the operating status of injection device 1, for instance asfeedback to the user. For example, an acoustical signal may be launchedby acoustical signal generator 23 as a reminder for the next dose to beinjected or as a warning signal, for instance in case of misuse.Acoustical signal generator may for instance be embodied as a buzzer orloudspeaker. In addition to or as an alternative to acoustical signalgenerator 23, also a haptic signal generator (not shown) may be used toprovide haptic feedback, for instance by means of vibration.

Processor 24 controls a wireless unit 28, which is configured totransmit and/or receive information to/from another device in a wirelessfashion. Such transmission may for instance be based on radiotransmission or optical transmission. In some embodiments, the wirelessunit 28 is a Bluetooth transceiver. Alternatively, wireless unit 28 maybe substituted or complemented by a wired unit configured to transmitand/or receive information to/from another device in a wire-boundfashion, for instance via a cable or fibre connection. When data istransmitted, the units of the data (values) transferred may beexplicitly or implicitly defined. For instance, in case of an insulindose, always International Units (IU) may be used, or otherwise, theused unit may be transferred explicitly, for instance in coded form.

Processor 24 receives an input from a pen detection switch 30, which isoperable to detect whether the pen 1 is present, i.e. to detect whetherthe supplementary device 2 is coupled to the injection device 1.

A battery 32 powers the processor 24 and other components by way of apower supply 31.

The supplementary device 2 of FIG. 4 is thus capable of determininginformation related to a condition and/or use of injection device 1.This information is displayed on the display 21 for use by the user ofthe device. The information may be either processed by supplementarydevice 2 itself, or may at least partially be provided to another device(e.g. a blood glucose monitoring system).

The processor 24 constitutes a processor arrangement. The OCR reader 25constitutes a dose dialled detector operable to detect a dose ofmedicament dialled. The PCR reader 25 also constitutes a dose deliverydeterminer for determining that a dose of medicament has been delivered.The OCR reader 25 and the processor 24 together constitute a quantitydeterminer for determining a quantity of medicament that has beendelivered. The processor 24 provides a function of a clock configured todetermine a current time.

FIGS. 5a-5c are flowcharts of embodiments of methods according to thepresent invention. These methods may for instance be performed byprocessor 24 of supplementary device 2 (see FIGS. 2b and 4), but also bya processor of supplementary device 3 of FIG. 2b , and may for instancebe stored in program memory 240 of supplementary device 2, which may forinstance take the shape of tangible storage medium 60 of FIG. 6.

FIG. 5a shows method steps that are performed in scenarios as shown inFIGS. 3a and 3b , where information read by supplementary device 41 frominjection device 40 is provided to blood glucose monitoring system 42 or42′ without receiving information back from blood glucose monitoringsystem 42 or 42′.

The flowchart 500 starts for instance when the supplementary device isturned on or is otherwise activated. In a step 501, a type ofmedicament, for example insulin, provided by the injection device isdetermined, for instance based on colour recognition or based onrecognition of a code printed on injection device or a component thereofas already described above. Detection of the type of medicament may notbe necessary if a patient always takes the same type of medicament andonly uses an injection device with this single type of medicament.Furthermore, determination of the type of medicament may be ensuredotherwise (e.g. by the key-recess pair shown in FIG. 4 that thesupplementary device is only useable with one specific injection device,which may then only provide this single type of medicament).

In a step 502, a currently selected dose is determined, for instance byOCR of information shown on a dosage window of injection device asdescribed above. This information is then displayed to a user of theinjection device in a step 503.

In a step 504, it is checked if an ejection has taken place, forinstance by sound recognition as described above. Therein, a prime shotmay be differentiated from an actual injection (into a creature) eitherbased on respectively different sounds produced by the injection deviceand/or based on the ejected dose (e.g. a small dose, for instance lessthan a pre-defined amount of units, e.g. 4 or 3 units, may be consideredto belong to a prime shot, whereas larger doses are considered to belongto an actual injection).

If an ejection has taken place, the determined data, i.e. the selecteddose and—if Applicable—the type of medicament (e.g. insulin), is storedin the main memory 241, from where it may later be transmitted toanother device, for instance a blood glucose monitoring system. If adifferentiation has been made concerning the nature of the ejection, forinstance if the ejection was performed as a prime shot or as an actualinjection, this information may also be stored in the main memory 241,and possibly later transmitted. In the case of an injection having beenperformed, at step 505 the dose is displayed on the display 21. Alsodisplayed is a time since the last injection which, immediately afterinjection, is 0 or 1 minute. The time since last dose may be displayedintermittently. For instance, it may be displayed alternately with thename or other identification of the medicament that was injected, e.g.Apidra or Lantus.

If ejection was not performed at step 504, steps 502 and 503 arerepeated.

After display of the delivered dose and time data, the flowchart 500terminates.

FIG. 5b shows in more detail exemplary method steps that are performedwhen the selected dose is determined based on the use of optical sensorsonly. For instance, these steps may be performed in step 502 of FIG. 5a.

In a step 901, a sub-image is captured by an optical sensor such asoptical sensor 25 of supplementary device 2. The captured sub-image isfor instance an image of at least a part of the dosage window 13 ofinjection device 1, in which a currently selected dose is displayed(e.g. by means of numbers and/or a scale printed on the sleeve 19 ofinjection device 1, which is visible through the dosage window 13). Forinstance, the captured sub-image may have a low resolution and/or onlyshow a part of the part of sleeve 19 which is visible through dosagewindow 13. For instance, the captured sub-image either shows the numbersor the scale printed on the part of sleeve 19 of injection device 1which is visible through dosage window 13. After capturing an image, itis, for instance, further processed as follows:

Division by a previously captured background image;

Binning of the image(s) to reduce the number of pixels for furtherevaluations;

Normalization of the image(s) to reduce intensity variations in theillumination;

Sheering of the image(s); and/or

Binarization of the image(s) by comparing to a fixed threshold.

Several or all of these steps may be omitted if applicable, for instanceif a sufficiently large optical sensor (e.g. a sensor with sufficientlylarge pixels) is used.

In a step 902, it is determined whether or not there is a change in thecaptured sub-image. For instance, the currently captured sub-image maybe compared to the previously captured sub-image(s) in order todetermine whether or not there is a change. Therein, the comparison topreviously captured sub-images may be limited to the sub-image of thepreviously captured sub-images that was captured immediately before thecurrent sub-image was captured and/or to the sub-images of thepreviously captured sub-images that were captured within a specifiedperiod of time (e.g. 0.1 seconds) before the current sub-image wascaptured. The comparison may be based on image analysis techniques suchas pattern recognition performed on the currently captured sub-image andon the previously captured sub-image. For instance, it may be analyzedwhether the pattern of the scale and/or the numbers visible through thedosage window 13 and shown in the currently captured sub-image and inthe previously captured sub-image is changed. For instance, it may besearched for patterns in the image that have a certain size and/oraspect ratio and these patterns may be compared with previously savedpatterns. Steps 901 and 902 may correspond to a detection of a change inthe captured image.

If it is determined in step 902 that there is a change in the sub-image,step 901 is repeated. Otherwise in a step 903, an image is captured byan optical sensor such as optical sensor 25 of supplementary device 2.The captured image is for instance an image of the dosage window 13 ofinjection device 1, in which a currently selected dose is displayed(e.g. by means of numbers and/or a scale printed on the sleeve 19 ofinjection device 1, which is visible through the dosage window 13). Forinstance, the captured image may have a resolution being higher than theresolution of the captured sub-image. The captured image at least showsthe numbers printed on the sleeve 19 of injection device 1 which arevisible through the dosage window 13.

In a step 904, optical character recognition (OCR) is performed on theimage captured in step 903 in order to recognize the numbers printed onthe sleeve 19 of injection device 1 and visible through the dosagewindow 13, because these numbers correspond to the (currently) selecteddose. In accord to the recognized numbers, the selected dose isdetermined, for instance by setting a value representing the selecteddose to the recognized numbers.

In a step 905, it is determined whether or not there is a change in thedetermined selected dose and, optionally, whether or not the determinedselected dose does not equal zero. For instance, the currentlydetermined selected dose may be compared to the previously determinedselected dose(s) in order to determine whether or not there is a change.Therein, the comparison to previously determined selected dose(s) may belimited to the previously determined selected dose(s) that weredetermined within a specified period of time (e.g. 3 seconds) before thecurrent selected dose was determined. If there is no change in thedetermined selected dose and, optionally, the determined selected dosedoes not equal zero, the currently determined selected dose isreturned/forwarded for further processing (e.g. to processor 24).

Thus, the selected dose is determined if the last turn of the dosageknob 12 is more than 3 seconds ago. If the dosage knob 12 is turnedwithin or after these 3 seconds and the new position remains unchangedfor more than 3 seconds, this value is taken as the determined selecteddose.

FIG. 5c shows in more detail method steps that are performed when theselected dose is determined based on the use of acoustical and opticalsensors. For instance, these steps may be performed in step 502 of FIG.5 a.

In a step 1001, a sound is captured by an acoustical sensor such asacoustical sensor 27 of supplementary device 2.

In a step 1002, it is determined whether or not the captured sound is aclick sound. The captured sound may for instance be a click sound thatoccurs when a dose is dialled by turning dosage knob 12 of injectiondevice 1 and/or when a dose is ejected/injected by pressing injectionbutton 11, and/or when a prime shot is performed. If the captured soundis not a click sound, step 1001 is repeated. Otherwise in a step 1003,an image is captured by an optical sensor such as optical sensor 25 ofsupplementary device 2. Step 1003 corresponds to step 903 of flowchart900.

In a step 1004, an OCR is performed on the image captured in step 1003.Step 1004 corresponds to step 904 of flowchart 900.

In a step 1005, it is determined whether or not there is a change in thedetermined selected dose and, optionally, whether or not the determinedselected dose does not equal zero. Step 1005 corresponds to step 905 offlowchart 900.

There might be a slight advantage of the acoustic approach shown in FIG.5c when it comes to power consumption of the supplementary device,because permanently capturing images or sub-images as shown in FIG. 5btypically is more power consuming than listening to an acoustical sensorsuch as a microphone.

FIG. 6 is a schematic illustration of a tangible storage medium 60 (acomputer program product) that comprises a computer program 61 withprogram code 62 according to aspects of the present invention. Thisprogram code may for instance be executed by processors contained in thesupplementary device, for instance processor 24 of supplementary device2 of FIGS. 2a and 4. For instance, storage medium 60 may representprogram memory 240 of supplementary device 2 of FIG. 4. Storage medium60 may be a fixed memory, or a removable memory, such as for instance amemory stick or card.

Finally, FIG. 7 is an information sequence chart 7 that illustrates theflow of information between various devices (e.g. the injection device 1and the supplementary device 2 of FIG. 4 in a scenario as depicted inFIG. 3a or 3 b) according to an embodiment of the present invention. Acondition and/or use of injection device 1 affects an appearance of itsdosage window, sounds generated by injection device 1 and a colour ofthe housing. This information is transformed by sensors 25, 26, 27, 30of supplementary device 2 into an OCR signal, an acoustic sensor signaland a photometer signal, respectively, which are in turn transformedinto information on the dialled dose, on an injection/dialling operationand on the type of insulin by a processor 24 of supplementary device 2,respectively. This information is then provided by supplementary device2 to a blood glucose monitoring system 42. Some or all of thisinformation is displayed to a user via the display 21.

As described in detail above, embodiments of the present invention allowconnection of a standard injection device, in particular an insulindevice, with a blood glucose monitoring system in a useful andproductive way.

Embodiments of the present invention introduce a supplementary device toallow for this connection, assuming the blood glucose monitoring systemhas wireless or other communication capabilities.

The benefits from the connection between the blood glucose monitoringand an insulin injection device are inter alia the reduction of mistakesby the user of the injection device and a reduction of handling steps—nomore manual transfer of the injected insulin unit to a blood glucosemonitoring is required, in particular to a blood glucose monitoringsystem with functionality of providing guidance for the next dose basedon the last dose injected and latest blood glucose values.

As described with reference to exemplary embodiments above, when auser/patient gets a new insulin pen, the user attaches the supplementarydevice to the pen. The supplementary device reads out the injected dose.It may also transfer it to a blood glucose monitoring system withinsulin titration capabilities. For patients taking multiple insulins,the supplementary device recognizes the device structure to the insulintype and may also transmit this piece of information to the bloodglucose monitoring system.

In example embodiments, the information shown on a display, for exampleLCD display 21 of FIGS. 2a and 4, may also converted to a sound signalplayed to a user through a speaker, for example by a text-to-speechfunctionality implemented by processor 24 using the acoustical signalgenerator 23. Thus, a user with impaired vision may have improved accessto the information of supplementary device 2, such as a dialled dose, arecommended dose, a recommended time for administration and/or the like.

When using embodiments of the present invention, the user inter alia hasthe following advantages:

The user can use the most convenient disposable insulin injector.

The supplementary device is attachable and detachable (reusable).

Injected dose information may be transferred to the blood glucosemonitoring system automatically (no more transfer mistakes). Improveddose guidance may result from this as the blood glucose monitoringsystem calculates the dose to be taken.

Keeping of a manual data logbook may not be needed any more.

Furthermore, when deploying the supplementary device proposed by thepresent invention, patients may also be reminded of injecting their nextdose by receiving an alarm signal, for instance, after an appropriatetime after a first dose of a medicament (for instance insulin orheparin) has been injected.

Injected dose information may be transferred to any computerized system,for instance as input for any dose calculation or any other applicabletherapeutic guidance calculation, or for the creation of an alarmsignal, for instance to remind the user of taking the next dose.

The term “drug” or “medicament”, as used herein, means a pharmaceuticalformulation containing at least one pharmaceutically active compound,

wherein in one embodiment the pharmaceutically active compound has amolecular weight up to 1500 Da and/or is a peptide, a proteine, apolysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody or afragment thereof, a hormone or an oligonucleotide, or a mixture of theabove-mentioned pharmaceutically active compound,

wherein in a further embodiment the pharmaceutically active compound isuseful for the treatment and/or prophylaxis of diabetes mellitus orcomplications associated with diabetes mellitus such as diabeticretinopathy, thromboembolism disorders such as deep vein or pulmonarythromboembolism, acute coronary syndrome (ACS), angina, myocardialinfarction, cancer, macular degeneration, inflammation, hay fever,atherosclerosis and/or rheumatoid arthritis,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one peptide for the treatment and/or prophylaxis ofdiabetes mellitus or complications associated with diabetes mellitussuch as diabetic retinopathy,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one human insulin or a human insulin analogue orderivative, glucagon-like peptide (GLP-1) or an analogue or derivativethereof, or exendin-3 or exendin-4 or an analogue or derivative ofexendin-3 or exendin-4.

Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) humaninsulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) humaninsulin; Asp(B28) human insulin; human insulin, wherein proline inposition B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein inposition B29 Lys may be replaced by Pro; Ala(B26) human insulin;Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) humaninsulin.

Insulin derivates are for example B29-N-myristoyl-des(B30) humaninsulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl humaninsulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin;B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30human insulin; B29-N-(N-palmitoyl-Y-glutamyl)-des(B30) human insulin;B29-N-(N-lithocholyl-Y-glutamyl)-des(B30) human insulin;B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin andB29-N-(ω-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1-39), a peptide of the sequenceH-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

Exendin-4 derivatives are for example selected from the following listof compounds:

H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

des Pro36 Exendin-4(1-39),

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),

wherein the group -Lys6-NH2 may be bound to the C-terminus of theExendin-4 derivative;

or an Exendin-4 derivative of the sequence

des Pro36 Exendin-4(1-39)-Lys6-NH2 (AVE0010),

H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,

des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,

des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,

H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25]Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(S1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2;

or a pharmaceutically acceptable salt or solvate of any one of theaforementioned Exendin-4 derivative.

Hormones are for example hypophysis hormones or hypothalamus hormones orregulatory active peptides and their antagonists as listed in RoteListe, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin,Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin),Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin,Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid,a heparin, a low molecular weight heparin or an ultra low molecularweight heparin or a derivative thereof, or a sulphated, e.g. apoly-sulphated form of the above-mentioned polysaccharides, and/or apharmaceutically acceptable salt thereof. An example of apharmaceutically acceptable salt of a poly-sulphated low molecularweight heparin is enoxaparin sodium.

Antibodies are globular plasma proteins (˜150 kDahttp://en.wikipedia.org/wiki/Dalton_%28unit%29) that are also known asimmunoglobulins which share a basic structure. As they have sugar chainsadded to amino acid residues, they are glycoproteins. The basicfunctional unit of each antibody is an immunoglobulin (Ig) monomer(containing only one Ig unit); secreted antibodies can also be dimericwith two Ig units as with IgA, tetrameric with four Ig units liketeleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

The Ig monomer is a “Y”-shaped molecule that consists of fourpolypeptide chains; two identical heavy chains and two identical lightchains connected by disulfide bonds between cysteine residues. Eachheavy chain is about 440 amino acids long; each light chain is about 220amino acids long. Heavy and light chains each contain intrachaindisulfide bonds which stabilize their folding. Each chain is composed ofstructural domains called Ig domains. These domains contain about 70-110amino acids and are classified into different categories (for example,variable or V, and constant or C) according to their size and function.They have a characteristic immunoglobulin fold in which two β sheetscreate a “sandwich” shape, held together by interactions betweenconserved cysteines and other charged amino acids.

There are five types of mammalian Ig heavy chain denoted by α, δ, ε, γ,and μ. The type of heavy chain present defines the isotype of antibody;these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies,respectively.

Distinct heavy chains differ in size and composition; α and γ containapproximately 450 amino acids and δ approximately 500 amino acids, whileμ and ε have approximately 550 amino acids. Each heavy chain has tworegions, the constant region (C_(H)) and the variable region (V_(H)). Inone species, the constant region is essentially identical in allantibodies of the same isotype, but differs in antibodies of differentisotypes. Heavy chains γ, α and δ have a constant region composed ofthree tandem Ig domains, and a hinge region for added flexibility; heavychains μ and ε have a constant region composed of four immunoglobulindomains. The variable region of the heavy chain differs in antibodiesproduced by different B cells, but is the same for all antibodiesproduced by a single B cell or B cell clone. The variable region of eachheavy chain is approximately 110 amino acids long and is composed of asingle Ig domain.

In mammals, there are two types of immunoglobulin light chain denoted byλ and κ. A light chain has two successive domains: one constant domain(CL) and one variable domain (VL). The approximate length of a lightchain is 211 to 217 amino acids. Each antibody contains two light chainsthat are always identical; only one type of light chain, κ or λ, ispresent per antibody in mammals.

Although the general structure of all antibodies is very similar, theunique property of a given antibody is determined by the variable (V)regions, as detailed above. More specifically, variable loops, threeeach the light (VL) and three on the heavy (VH) chain, are responsiblefor binding to the antigen, i.e. for its antigen specificity. Theseloops are referred to as the Complementarity Determining Regions (CDRs).Because CDRs from both VH and VL domains contribute to theantigen-binding site, it is the combination of the heavy and the lightchains, and not either alone, that determines the final antigenspecificity.

An “antibody fragment” contains at least one antigen binding fragment asdefined above, and exhibits essentially the same function andspecificity as the complete antibody of which the fragment is derivedfrom. Limited proteolytic digestion with papain cleaves the Ig prototypeinto three fragments. Two identical amino terminal fragments, eachcontaining one entire L chain and about half an H chain, are the antigenbinding fragments (Fab). The third fragment, similar in size butcontaining the carboxyl terminal half of both heavy chains with theirinterchain disulfide bond, is the crystalizable fragment (Fc). The Fccontains carbohydrates, complement-binding, and FcR-binding sites.Limited pepsin digestion yields a single F(ab′)2 fragment containingboth Fab pieces and the hinge region, including the H—H interchaindisulfide bond. F(ab′)2 is divalent for antigen binding. The disulfidebond of F(ab′)2 may be cleaved in order to obtain Fab′. Moreover, thevariable regions of the heavy and light chains can be fused together toform a single chain variable fragment (scFv).

Pharmaceutically acceptable salts are for example acid addition saltsand basic salts. Acid addition salts are e.g. HCl or HBr salts. Basicsalts are e.g. salts having a cation selected from alkali or alkaline,e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), whereinR1 to R4 independently of each other mean: hydrogen, an optionallysubstituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenylgroup, an optionally substituted C6-C10-aryl group, or an optionallysubstituted C6-C10-heteroaryl group. Further examples ofpharmaceutically acceptable salts are described in “Remington'sPharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), MarkPublishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia ofPharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

FIG. 8 is a drawing that will now be used to illustrate operation of thesupplemental device 2. FIG. 8 is part flowchart and part state diagram.

In the following, user inputs are denoted with reference numeralscommencing “I”, displays or states are denoted with reference numeralscommencing with “D”, and other elements of the drawing, for instancechecks made by the supplemental device and explanatory information, aredenoted by reference numerals commencing with “E”.

In the following, the display 21 is referred to as the LCD 21, so as toavoid confusion between the hardware display 21 and the image that isdisplayed, and which may be termed a display. However, the LCD 21 may beany suitable form of display hardware.

Initially, the supplemental device is powered off. This provides thedisplay shown in D1.

D1 also goes to show the general arrangement of the user interfacefeatures of the supplemental device. In particular, an uppermost surfaceof the supplemental device 2 is shown provided with the LCD 21 and theconfirm/OK button 34. The confirm/OK button 34 is located to the left ofthe LCD 21 in this example, although it may have an alternative locationin other embodiments. The power on/off button 22 and the communicationsbutton 33 are located on the side of the supplemental device 2. As shownhere, the communications button 34 and the power on/off button 22 arelocated on the same side of the supplemental device 2, although in otherembodiments the buttons are located differently. For instance, in someembodiments, the power on/off button 22 is located on the opposite sideof the LCD 21 to the communications button 33. In some otherembodiments, the communications button 33 and/or the power on/off button22 are located on the top surface of the supplemental device 2.

At input I1, the user presses the power on/off button 22. The input I1is detected by the supplemental device 2. In particular, the processor24 detects that the power on/off button 22 has been pressed for arelatively short period. Other user inputs are detected by thesupplemental device in a similar manner, and short hand explanation isoccasionally provided in the following explanation. In the following,‘mode’ and ‘state’ are used interchangeably to denote the same thing; ifthe supplemental device 2 is in mode X it means the same as it being instate X.

If when the supplemental device 2 is in the state illustrated in D1, thesupplemental device 2 receives a long press of the power on/off button22, denoted at input I2 in FIG. 8, the supplemental device 2 transitionsto the state or display shown at D2. Here, a power on progress bar isdisplayed on the LCD 21. This progress bar includes a symbol denotingpower or a battery and also includes an indicator relating to the powerlevel of the battery. As shown in FIG. 8, the battery power isapproximately one third of the full battery in this example. Thesupplemental device 2 remains in the state indicated by D2 for apredetermined time, for instance 2 or 3 seconds. Following the stateindicated in D2, the supplemental device 2 transitions to one of fourpossible states.

If the supplemental device is not mounted on the injection device 1, asis detected by the supplemental device by the processor 24 examining astate of the detection switch 30, the supplemental device 2 transitionsto the state indicated by D3 in FIG. 8. Here, the supplemental deviceprovides on the LCD 21 a graphic indicating that no pen is present. Thismay be purely graphical, purely textural, or a combination of graphicsand text.

If when the supplemental device 2 is in the state indicated by D2, thesupplemental device 2 detects that there is not correct alignmentbetween the supplemental device 2 and the injection pen 1, thesupplemental device progresses to the state indicated by D4 in FIG. 8.An incorrect alignment between the supplemental device 2 and theinjection device 1 may be detected by the supplemental device byexamination of the symbols received by the OCR module 25 and/or thephotometer 26.

Thirdly, if the supplemental device when in the state indicated by D2detects that the battery 32 is almost empty, the supplemental devicetransitions to a low battery state indicated by D5 in FIG. 8. Here, abattery warning graphic is provided. This may take any suitable form.

If the supplemental device 2 does not transition into any of the threestates indicated by D3, D4 and D5 in FIG. 8, it transitions to the stateindicated by D6. This is called the default state. In the default state,the supplemental device indicates details of the last injection. Putanother way, in the default state, the supplemental device 2 displaysinformation relating to the last use of the injection pen 1.

The default state D6 is also arrived at following the unmounted stateindicated by D3, the incorrect alignment state indicated by D4 or thelow battery state indicated by D5. The supplemental device 2 may remainin any of these preceding states for a predetermined time, for instance3 seconds, 5 seconds or 10 seconds, before transitioning to the defaultstate, shown in D6.

In the case of the unmounted state indicated by D3, the supplementaldevice 2 may instead refrain from transitioning to the default stateindicated by D6 until the supplemental device 2 detects that there iscorrect alignment between the supplemental device 2 and the injectionpen 1. Alternatively, after the supplemental device has transitionedthrough the unmounted state indicated by D3, the supplemental device mayremain in the default state indicated by D6 until the supplementaldevice detects, by examining the state of the detection switch 30, thatthe supplemental device 2 is mounted on the injection device 1.

With respect to the unaligned state indicated by display D4 in FIG. 8,the supplemental device 2 may remain in the unaligned state until thesupplemental device 2 detects correct alignment between the supplementaldevice 2 and the injection device 1. Alternatively, the supplementaldevice 2 may transition from the unaligned state indicated by D4 to thedefault state indicated by D6 but refrain from progressing from thedefault state until the supplemental device 2 detects that there iscorrect alignment between the supplemental device 2 and the injectiondevice 1.

If the supplemental device has transitioned through the low batterystate indicated by D5 before arriving at the default state indicated byD6 in FIG. 8, the supplemental device 2 indicates periodically thatthere is a low battery state. This is achieved by a check step E1 thatdepends from the default state D6. The check step E1 involves thesupplemental device 2 determining whether the battery 32 is almost emptyand, if so, an action step E2 involves providing the warning shown inthe display D5 periodically.

Even if the supplemental device 2 did not transition through the lowbattery state indicated by D5 before arriving at the default stateindicated by D6, the check step E1 is performed periodically. Thus, whenthe supplemental device 2 is in the default state, indicated by D6 inFIG. 8, and the battery level falls such that at the check step E1 it isdetermined that the battery is almost empty, action step E2 involvescausing the supplemental device 2 to transition to the low battery stateindicated by D5.

Once the low battery state D5 has been transitioned through, the lowbattery display indicated by D5 is provided periodically until thebattery 32 is replaced or otherwise replenished. In some embodiments,the low battery display indicated in D5 is provided only when thesupplemental device 2 is in the default state. This prevents the lowbattery warning being provided to the user when the device is in use inconnection with delivery of a dose of medicament and/or when thesupplemental device 2 is attempting to communicate with another device.

Although not shown in FIG. 8, if when the supplemental device 2 is inthe default state, indicated by D6 in the Figure, the supplementaldevice 2 receives a long press of the power on/off button 22, thesupplemental device powers down. Thereafter, the device is in the offstate that is indicated by D1 in FIG. 8. The supplemental device 2 maybe responsive to a long press of the power on/off button 22 to powerdown from any state.

The supplemental device 2 may transition from the default stateindicated by D6 in response to detecting that the user has turned thedosage dial 12. This is indicated at I3 in the Figure. In response, thesupplemental device 2 enters a dosage dialling state, which is indicatedat D7 in FIG. 8. Here, the supplemental device 2 displays on the LCD 21the dose medicament that is currently dialled into the injection pen 1.This is known by the supplemental device 2 by virtue of reading of theFIG. 19 from the injection device by the OCR reader 25. In this state,the supplemental device 2 also displays an indication of the medicamentthat is present within the injection device 1. In the display D7, themedicament is indicated through the display of text that names themedicament, in this case “Apidra”.

The currently set dose is indicated in the dosage dialling state in thedisplay shown in D7 in any suitable way. The dose advantageously isindicated in the largest characters that can be accommodated by the LCD21. In particular, the height of the letters may be equal to the heightof the LCD 21, or at least have a height that is 80 or 90% or more ofthe height of the LCD 21. The supplemental device may provide thedisplay D7 in such a way as to make it clear to the user that the dosevalue displayed on the LCD 21 relates to a dose that is currentlydialled into the injection pen in any suitable way. For instance,graphical elements provided around the displayed dose value may blink orflash. Alternatively, the characters of the dose value themselves mayblink or flash. Alternatively, the background may blink or flash.

When the supplemental device 2 detects that the dosage dial 12 has notbeen turned for a predetermined period, for instance 0.5 seconds or 1second, this is detected at input I3 a (although it is actually absenceof an input) and the supplemental device 2 transitions to a dose dialledstate, which is indicated by the dialled dose display D7 a in FIG. 8. Inthe dose dialled state, the supplemental device 2 causes the LCD 21 toprovide two different displays, with the device 2 transitioning from onedisplay to the other display and back again on a periodic basis. In thedose dialled state indicated by D7 a, both displays include the dialleddose, and this is provided in the same location. The dialled dose may bedisplayed in the same way in both of the displays. One display indicatesthe medicament that is present in the injection device 1. In thisexample, this is indicated by text that names the medicament, in thiscase “Apidra”. The other display includes an indication that a dose ofmedicament may be delivered. In this example, this is provided by agraphic of a hand with a confirm/OK button.

If while in the dose dialled state illustrated by D7 a the supplementaldevice 2 receives an input relating to further turning of the dosagedial 12, indicated by input I3 in FIG. 8, the supplemental device againproceeds to the dosage dialling state that is indicated by D7 in theFigure.

If the supplemental device 2 detects that the confirm/OK button 34 hasbeen operated by a user when the device is either in the dosage diallingstate indicated by D7 or in the dose dialled state indicated by D7 a,this input I4 causes transition to an inject now state, which isindicated by D8 in FIG. 8. In the inject now state, a graphic isprovided indicating to the user that injection is possible.

At this stage, the user has two options. They may change the dose. Thisis achieved by the user selecting the confirm/OK button 34 and thenturning the dosage dialler 12. This is detected as an input I5 by thesupplemental device. In detecting the input I5, the supplemental device2 reverts to the dose dialled state indicated by D7 in FIG. 8.

Alternatively, the user can inject the medicament. This is detected bythe supplemental device 2 as an input I6. Input I6 causes transition toa dosage delivery state, indicated as D9 in FIG. 8. Here, the doseremaining dialled into the injection device 1 is displayed on the LCD21. As the dose is delivered, the dose remaining becomes smaller. Assuch, the remaining dose value counts down from the dialled in dosetowards zero.

If the user does not deliver the entire dose, this is detected by thesupplemental device at input I7 either by detecting depression of theconfirm/OK button 34 or by detecting that the user has turned back thedosage dialler 12. The input I7 causes transition to a ten secondcountdown state, indicated at the display D10 in the Figure. After theten seconds have lapsed, the supplemental device 2 transitions to apartial dose delivered state, indicated by a display D11 in FIG. 8.Here, the supplemental device 2 displays the dose delivered to the userthrough the injection pen 1. The dose delivered is equal to the dosethat was dialled in, as detected by the supplemental device when in thedosage dialling state indicated by D7 or the dialled dose stateindicated by D7 a, minus the dose remaining when the input I7 wasdetected. In this state, the medicament that was delivered also isdisplayed. In this example, the delivered dose is indicated incharacters that are smaller than the characters provided by either ofthe states indicated by D7 and D7 a in FIG. 8. Arranged vertically withrespect to the delivered dose is an indication of the medicament thatwas delivered. On transitioning to or from this state, a timer (notshown) within the supplemental device is reset. The timer allows thesupplemental device 2 to calculate an elapsed time since a last dose wasdelivered. Transition from the state indicated by display D11 is to thestate indicated by D7 in FIG. 8.

Alternatively, the supplemental device 2 may exit the dose deliverystate indicated by D9 by detecting an input I8 indicative of theinjection having been completed. In this case, the supplemental devicetransitioned to a countdown state that is indicated by the display D12in FIG. 8. Here, the LCD 21 is provided with an icon that is the same asthe icon provided in the display of the countdown state indicated by D10in the Figure.

After ten seconds have elapsed, the supplemental device 2 transitions toa remove needle instruction state, indicated at the display D13 in FIG.8. Here, the supplemental device 2 provides a graphic that indicates tothe user that the needle of the injection device 1 should be replaced.After a predetermined time, or upon detecting that the needle has beenreplaced if the acoustical sensor 27 is present, the supplemental device2 transitions to a reset state that is indicated by the display D14 inFIG. 8. Here, the value of the delivered dose is stored in thesupplemental device 2 and a timer (not shown) is started. The timerprovides a value that is indicative of the time elapsed since the lastdose. After the reset state, the supplemental device 2 transitions tothe default state, indicated by D6 in FIG. 8.

If when the supplemental device 2 is in the default state, indicated byD6, it detects an input I9 indicating that the user has pressed thecommunication button 33, it transitions from the default state. Here,the supplemental device 2 determines whether a device is accessible. Adevice here is for instance the blood glucose measurement unit 42. If adetermination at step S3 indicates that a device is accessible and it isdetermined in E4 that the device is unknown, the supplemental device 2enters a pairing process state, which is indicated by D15 in the Figure.In this state, the supplemental device 2 initiates pairing with thedetected device. In the case of the wireless unit 28 being a Bluetoothtransceiver, this involves initiating pairing in accordance with theBluetooth standard. In the pairing process state, indicated by D15, aBluetooth PIN number is displayed on the LCD 21. This is accompaniedwith an icon requesting that the user confirm that the PIN numbermatches with one displayed on the unknown device. If the supplementaldevice 2 determines at E5 that pairing has failed, the supplementaldevice 2 transitions to a Bluetooth error message state, indicated byD16 in the Figure. This state is also transitioned to following input I9if it is determined at E8 that no device is accessible. In the Bluetootherror message state, indicated by D16, an icon is displayed on LCD 21indicating that no communication is possible. Following the Bluetootherror message state, for instance after a predetermined time, thesupplemental device 2 transitions to the default state, indicated by D6.

If in the pairing state the supplemental device at E6 determines thatpairing has been completed, it transitions to a short transmissionstate, indicated by D17. The supplemental device also transmissions tothe short transmission state indicated by D17 from the default stateindicated by D6 following input I9 if the supplemental device determinesthat a device is accessible at E3 and at E7 determines that it is aknown device.

In the short transmission state, indicated by D17, an icon or graphic isdisplayed on the LCD 21 indicating that communication is in process.Once communication is complete, the supplemental device 2 transitions toa transmission done stage, indicated by D18. Here, the supplementaldevice 2 provides a graphic indicating that transmission has beencompleted. Following the transmission done state, the supplementaldevice 2 transitions to the default state, indicated by D6.

When in the default state, indicated by D6, operation is as follows. Thesupplemental device 2 is expected to be in the default state for most ofthe time for which it is powered on. As such, the displays D6 when inthe default state are the displays that are likely to be seen most by auser of the supplemental device.

When in the default state, the supplemental device is configured toindicate to the user details of the last delivered dose. The detailsinclude the quantity of the dose and the time elapsed since the lastdose delivery. These details also include the identity of themedicament.

In these embodiments, this is achieved by transitioning between twodifferent displays in the default state. The first display is shownuppermost in display D6 in FIG. 8. Here, it will be seen that there aretwo regions of the LCD 21. A region on the left side occupiesapproximately two thirds of the area of the display. This region ishereafter termed the last dose region. On the right side of the LCD 21,to the right of the last dose region, is another region. The otherregion in this example displays a dose that is dialled into theinjection pen 1. The information displayed on the right side of the LCD21 is the dialled value from the injection pen 1. This is not influencedby the information displayed on the left side of the LCD 21.

The last dose region in the first display, shown uppermost in D6 in FIG.8, is divided into two areas. Here, they are upper and lower areas. In afirst area, here the lower area, the last delivered dose is displayed.This is in the form of a number, indicating the dose in IUs.

In the second area, the elapsed time since the last dose delivered isdisplayed. Here, this is displayed as a time expressed as a number andwith a unit of time expressed in Roman characters. Display of the unitof time allows a user to distinguish between the display of the timesince the last dose and the quantity of the dose. The second area alsoincludes a graphic indicating a timer or clock, which reinforces thismessage.

In the second display, shown lowermost in D6 in FIG. 8, the first areais unchanged. The first area thus displays the quantity of the lastdose. The second area does not show the time elapsed since the lastdose. Instead, it shows the medicament of the last dose. Here, this isindicated by text that spells the name of the medicament, in this case“Apidra”. The clock or timer icon is again displayed in the second area.

In the default state, the supplemental device 2 causes the display totransition between the first and second displays, shown uppermost andlowermost respectively, periodically. Transitioning may occur every twoseconds, for instance.

As can be seen in FIG. 8, the first area of the dose display region 21Bis larger than the second area. As such, the height of the charactersused to indicate the quantity of the dose are larger than the charactersused to indicate the time elapsed since the last dose or the identity ofthe medicament. As such, a user is able to determine quickly and easily,perhaps with only a glance, the quantity of the last dose.

Additionally, the user is able to determine relatively easily the timeelapsed since the last dose. It is the time elapsed since the last doseand the quantity of the dose that are the parameters that are most ofinterest to users of medicaments that are used to treat diabetes. It isthese parameters that are most of interest to the user when determiningthe next dose of medicament, in terms of the time when it should bedelivered and in terms of the quantity of medicament that may be needed.

As such, the provision of the default state and the displays provided inthat state by the supplemental device 2 can allow the user better totreat the condition for which the medicament is prescribed. Put anotherway, the features of the supplemental device when in the default statecan allow the user more easily to treat their condition, potentiallyproviding better treatment for the user.

An alternative embodiment will now be described with reference to FIGS.2c and 9.

As can be seen in FIG. 2c , the supplemental device 2 is provided with aLCD 21 and a power on/off button 22. The LCD 21 is a touch-sensitivedisplay, through which a user can provide input to the supplementaldevice. As such, the touch-sensitive LCD 21 also provides the functionsprovided by the communications button 33 and the confirm/OK button 34 inthe embodiment of FIG. 8 and FIG. 2 b.

Operation of the supplemental device according to this embodiment isquite similar to the operation of the device of FIG. 2b , as describedwith reference to FIG. 8. In FIG. 9, reference numerals are retainedfrom FIG. 8 for like elements, and only the differences betweenoperation of the embodiment of FIG. 2c and the embodiment of FIG. 2bwill be described here. For features and operation of the device of FIG.2c that are the same as features and operations of the device of FIG. 2band FIG. 8, no discussion is made in the following.

The device off state, illustrated by display D1 in FIG. 9 is verysimilar to the corresponding state of the device operation shown in FIG.8. This display D1 illustrates the overall layout provided on the LCD21. In particular, a first region 21B of the display is a display region21B. This is shown on the right of the display of D1 of FIG. 9. A secondregion 21A of the display is an input region 21A. This is shown on theleft in D1. The input region 21A is also an active display region 21B.However, the input region 21A is a region where user inputs may bereceived. The input region 21A includes a display of a virtual button atappropriate times, in particular when the supplemental device 2 is incertain states. The input region 21A in this embodiment is alwayslocated in the same place on the LCD 21. This simplifies the experiencefor the user. In other embodiments, the input region 21A may change inlocation depending on the state of the supplemental device. The inputregion 21A is the touch sensitive input 35 shown in FIG. 2 c.

In the device off state shown in D1, the LCD 21 is blank. When the LCD21 is blank in a region, nothing is displayed in that region. When theinput region 21A is blank, an outline of the virtual button may bedisplayed, although nothing is displayed within the virtual button.

In the power off progress state shown by D2, the input region 21A isleft blank, that is nothing is displayed in the input region 21A. Inthis state, the display region 21B is provided with an indicator thatindicates the amount of power remaining in the battery 32. Thisindicator is the same as the indicator shown in D2 of FIG. 8, althoughit is smaller in size.

In the device not mounted state D3, the input region 21A is blank, and agraphic indicating that the pen is not connected is shown in the displayregion 21B. In the camera adjustment issue state shown at D4, the inputregion 21A is left blank and the display region 21B indicates that thereis not alignment between the supplemental device 2 and the injectiondevice 1. In the battery low state indicated by display D5, the inputregion 21A is left blank and the display region 21B includes an iconindicating that the battery is almost empty.

In the default state, the input region 21A is provided with an iconrelating to communication options. In this example, the input region 21Ais provided with an icon indicating a Bluetooth communication option.The supplemental device 2 is configured when in the default state torespond to a user input I9 comprising touching of the LCD 21 at theinput region 21A to proceed through the checks E3 and E8, as describedabove with reference to FIG. 8.

When in the default mode, the display region 21B of the display isprovided with the displays as described above in relation to the firstregion of the display in the default state of FIG. 8.

If the supplemental device 2 detects that the battery is almost emptywhen the device is in the default state shown by D6, the check E1 maycause an action E2 which results in transitioning of the device to thebattery almost empty state, providing a display shown in D5,periodically. Alternatively, the supplemental device 2 may be configuredto include a low battery icon within the display region 21B. This isindicated by the display D19 in FIG. 9.

When in the currently set value state indicated by the display D7 inFIG. 9, the currently dialled dose is displayed in the display region21B. The input region 21A is provided with a graphic, which in this caseis the word “OK”. When in this mode, the supplemental device 2 isresponsive to detection of a user input at the input region 21A of theLCD 21, represented by input I4 in FIG. 9, to transition to the injectnow state, illustrated by display D8 in FIG. 9. In the inject now state,the input region 21A is provided with an indication of the dialled dose.The display region 21B is provided with an icon which is the same as theicon shown in D8 of FIG. 8. After an injection input I8, the numberdisplayed within the input region 21A counts down, reflecting theremaining dialled dose.

The supplemental device 2 is responsive to detection of a user input atthe input region 21A of the LCD 21, indicated by input I7 in FIG. 9, totransition to the countdown state indicated by D10 in the Figure.

In the display indicated by display D11 in FIG. 9, the delivered dose isdisplayed, along with an indication of the medicament delivered.

In the countdown states indicated by the displays D10 and D12 in FIG. 9,the input region 21A of the LCD 21 is left blank. This is the case alsofor the remove needle state instruction provided by D13 in FIG. 9. Inthese states, no transition occurs from user input, so it is appropriatefor the input region 21A of the LCD 21 to remain blank.

The communication error message state, indicated by D16, is similar tothe corresponding display of FIG. 8. However, the input region 21A ofthe LCD 21 includes the text “OK”. The supplemental device 2 isconfigured to transition from the communication error message stateshown by D16 to the default state shown by D6 after a predetermined timeor upon detecting a user input at the input region 21A of the LCD 21.

The text “OK” is provided at the input region 21A of the LCD 21 alsowhen in the pairing state, indicated by display D15 in FIG. 9. Thesupplemental device 2 is configured to respond to detection of a userinput at the input region 21A of the LCD 21 to transition either to thecommunication error message state shown by D16 or the short transmissionstate indicated by D17 depending on whether pairing has been achieved.Alternatively, transitioning may occur automatically, for instance inresponse to detection of a time out.

It will be appreciated from the above description of FIG. 9 thatoperation of the supplemental device of FIG. 2c is quite similar to theoperation of the device of FIG. 2b . However, the dynamic adjustment ofthe text or graphics control to be displayed in the input region 21A ofthe LCD 21 simplifies the process of use for the user. In particular,aside from the power on/off button 22, there is only ever one inputbutton/region 21A that needs to be operated by the user. Moreover, theconsequence of the user operating the input should be more obvious.

Additionally, the arrangement of the supplemental device 2 of FIG. 2c issuch that the user cannot operate the communications button other thanwhen the device is in the default state, indicated by D6. This preventsthe user believing that the supplemental device 2 might lead toactuation of the communications button 33 other than when in the defaultstate, shown by D6.

It will be appreciated that the above-described embodiments are merelyexamples and that numerous alternatives will be envisaged by the skilledperson and are within the scope of the present invention.

For instance, the communication states etc may be replaced byalternative states in which operation of the supplemental device 2 isquite different, or these states may be omitted altogether.

Referring to FIGS. 10 and 11, embodiments of the invention will now bedescribed. FIG. 10 shows a lateral cross-section taken through theinjection device 1 with supplemental device 2 attached. In FIG. 10, onlythe central part of the supplemental device 2 is shown; the mating unitwhich embraces the injection device 1 is omitted for clarity. The matingunit is configured to ensure that that supplementary device sits tightlyon a housing of an injection device. FIG. 11 shows an axialcross-section taken through the injection device 1 with supplementaldevice 2 attached. Some components of the supplemental device areomitted or shown in wireframe in FIG. 11 for clarity.

FIGS. 10 and 11 both show an electromechanical switch arrangement 110.In FIG. 10, the remained of the supplemental device 2 is not shown. Theelectromechanical switch arrangement 110 comprises a self-contained unitwhich is fitted to the supplemental device 2. The electromechanicalswitch arrangement 110 may for example be housed in a recess in theunderside of the supplemental device 2 (the part which contacts theinjection device 1). The electromechanical switch arrangement 110 may besecured to the supplemental device 2 by friction or by an interlockingarrangement (not shown), or alternatively by screws, adhesive or thelike.

The electromechanical switch arrangement 110 comprises a main body 111(also referred to herein as a housing 111). A cavity is defined insidethe main body 111. An upper part of the main body 111 is arranged toengage with the housing 20 of the supplemental device 2 to secure theelectromechanical switch arrangement 110 to the supplemental device 2. Alower part of the main body is concave in shape and matches thecurvature of the injection device 1. The lower part of the main body 111has an aperture.

In embodiments of the invention, the injection device 1 to which thesupplemental device 2 is to be attached has a corrugated dialling sleeve119. The corrugations are defined by troughs 116 and crests 117. Thedialling sleeve 119 is configured to rotate with the dosage knob 12during dose dialling. The dialling sleeve 119 may be coupled directly tothe injection button 11. The lower part of the main body 111 of theelectromechanical switch arrangement 110 abuts several of the crests 117of the corrugated dialling sleeve 119 but the dialling sleeve 119 isfree to rotate relative to the electromechanical switch arrangement 110.

A switch 113 (also referred to as a switching member 113 or switchinglever 113) is rotatably mounted inside the main body 111 of theelectromechanical switch arrangement 110. The switch 113 has aprotrusion 118 and is arranged such that this protrusion passes throughthe aperture in the main body 111 and protrudes from the main body 111.An internal spring 114 biases the switch 113 towards the position shownin FIG. 10, in which the switch 113 abuts an internal surface of themain body 111 and the end of the protrusion 118 abuts a trough 116 ofthe dialling sleeve 119. The internal spring 114 may for example be atorsion spring. Alternatively, a coil spring or a resilient arm couldbias the switch 113. In some embodiments, the injection device 1 isconfigured such that a small portion of the dialling sleeve 119 adjacentthe dosage button 12 extends out of the housing 10 of the injectiondevice 1 when no dose has been dialled. This allows the protrusion 118to contact the dialling sleeve 119 at all times during operation of thedevice.

The inner wall of the electromechanical switch arrangement 110 comprisestwo electrical contacts 112. These contacts are arranged to be engagedby corresponding electrical contacts on the switch 113. In someembodiments, the contacts 112 and/or the corresponding contacts on theswitching member 113 are sprung contacts. For example, a first of thecontacts 112 may be engaged at all times by a contact on the switch. Asecond of the contacts 112 is not engaged by the switch 113 when in theposition shown in FIG. 10. This second contact 112 is engaged by theswitch 113 only when the protrusion 118 of the switch 113 rides up acrest 117 of the dialling sleeve 119, causing the switch to rotatewithin the main body 111. When the switch 113 engages this secondcontact, an electrical connection is made through the switch between thetwo contacts 112. As previously described, the supplemental device 2comprises a processor 24. This processor 24 is configured to control theapplication of a signal to one of the contacts 112 and to detect whenthe circuit is completed by measuring a signal at the other of thecontacts 112.

The supplemental device 2 also comprises a compensation spring 115 (alsoreferred to herein as a biasing member), visible in FIG. 11. Thecompensation spring 115 forms part of the supplemental device 2, but isexternal to the electromechanical switch arrangement 110. Thecompensation spring 115 may be a torsion spring. The compensation spring115 has a first end 120 which is secured internally to the housing 20 ofthe supplemental device 2. The concave underside of the supplementaldevice 2 is shown in wireframe in FIG. 11. The compensation spring 115has a second end 121 which is secured to the electromechanical switcharrangement 110. The second end 121 of the compensation spring 115 maybe secured to an upper part of the electromechanical switch arrangement110 (relative to the orientation of shown in FIG. 11). The compensationspring 115 exerts a force on the electromechanical switch arrangement inthe direction of the arrow “A” on FIG. 11. This force causes theelectromechanical switch arrangement 110 to be biased towards theinjection device 1 and in particular towards the dose dialling sleeve119.

The compensation spring 115 may compensate for relative movement betweenthe supplemental device 2 and injection device 1 and/or between theelectromechanical switch arrangement 110 and supplemental device 2 asdescribed in greater detail below. These relative movements may be dueto manufacturing tolerances of the supplemental device 2,electromechanical switch arrangement 110 and injection device 1, inparticular the dose dialling sleeve 119, or may be an intentional designfeature.

Exemplary operation of the injection device 1 and supplemental device 2containing the electromechanical switch arrangement 110 will now bedescribed.

First the electromechanical switch arrangement 110 is secured to thesupplemental device 2. This may be done during manufacture of thesupplemental device 2. A user then fits the supplemental device 2 to theinjection device 1 as previously described. Once the supplemental device2 has been fitted to the injection device 1, the lower part of theelectromechanical switch arrangement 110 abuts the surface of theinjection device 1.

When a dose has been dialled into the injection device 1, theelectromechanical switch arrangement 110 abuts the dose dialling sleeve119, as depicted in FIGS. 10 and 11. The concave underside of theelectromechanical switch arrangement 110 contacts several crests 117 ofthe corrugated surface of the dialling sleeve 119. The dose diallingsleeve 119 has a smaller diameter than the outer housing 10 of theinjection device 1 and may have the same or a smaller diameter than thedosage knob 12.

Due to the action of the internal spring 114, the protrusion 118 of theswitching member 113 is forced to protrude through the aperture in themain body 111 of the electromechanical switch arrangement 110. Thus theprotrusion 118 may contact a trough 116 of the dose dialling sleeve 119while the electromechanical switch arrangement 110 rests on the crests117 of the sleeve.

A user then dials in a dose by grasping and rotating the dosage knob 12.The dose dialling sleeve 119 rotates relative to the supplemental device2. As the sleeve 119 rotates, the protrusion 18 of the switching member113 follows the contours of the dialling sleeve surface. When a crest117 is rotated past the aperture, the protrusion 118 rides up the crest,forcing the switching member 113 to rotate within the main body 111. Theswitching member 113 contacts the second of the contacts 112 when theprotrusion 118 reaches the top of a crest 117. The switching member 113may be in contact with the first of the contacts 112 at all times. Anelectrical path is formed between the two contacts 112 when theswitching member 113 engages with the second of the contacts 112. Theprocessor 24 detects that the switch has been closed by applying asignal at the first contact and measuring a signal at the secondcontact.

As the sleeve continues to rotate, the protrusion 118 rides down thecrest 117 and into the next trough 116 under action of the internalspring 114. The switching member 113 ceases to contact the secondcontact 112. The processor 24 determines from this sequence that oneunit (IU) has been dialled into the injection device 1. For each unitwhich is dialled into the injection device 1, the processor detects oneconnection of the circuit preceded and followed by a disconnection.

The switching point of the electromechanical switch arrangement 110,i.e. the point at which the switch 113 completes a circuit between thetwo contacts 112, occurs when the protrusion 118 rides up to the top ofa crest 117. The contacts 112 may be sprung contacts to allow some rangein the switching point. However, relative movement between thesupplemental device 2 and injection device 1 and/or between theelectromechanical switch arrangement 110 and supplemental device 2 maymean that the switching point is not reached when the protrusion 118reaches the top of a crest 117. This may be a result of manufacturingtolerances of the injection device 1, supplemental device 2 andelectromechanical switch arrangement 110.

The compensation spring 115 compensates for these tolerances by forcingthe main body 111 of the electromechanical switch arrangement 110against the dose dialling sleeve 119 surface. For example, theelectromechanical switch arrangement 110 may be secured to thesupplemental device 2 at only a single point, allowing some lateral orrotational movement between these two components. The supplementaldevice 2 may also have some degree of movement relative to the injectiondevice 1, even while secured to the injection device. The effect of anymanufacturing tolerances of these components is therefore removed.

The user then delivers the selected dose. During this procedure, thedose dialling sleeve 119 moves back into the injection device 1, butdoes not rotate. The dose dialling sleeve 119 is disconnected from thesleeve 19 and dosage knob 12 by an internal clutch coupled to theinjection button 11. Alternatively, the dose dialling sleeve 119 may becoupled directly to the injection button, which is itself disconnectedfrom the sleeve 19 and dosage knob 12 by the internal clutch. Thusduring dose delivery, the protrusion 118 of the switching member 113remains in the same trough 116 of the dose dialling sleeve 119 and nocircuit connection is made by the switching member 113.

The electromechanical switch arrangement 110 is provided in addition tothe OCR reader 25. If the processor 24, using the OCR reader 25, detectsthat the numbers on the sleeve 19 are changing, it is important also todetermine whether a dose is being dialled in (dose setting), dialled out(dose correction) or delivered (dose dispense). This determination isnot possible using the OCR reader 25 alone. Use of the electromechanicalswitch arrangement 110 allows this determination to be made.

The OCR reader 25 of this embodiment is one possible implementation of adose dialled detector operable to detect a dose of medicament dialledinto the attached injection device. Other implementations are feasible,using a position determination system for a member that moves when adose is dialled, wherein the positioning system comprises electricalcontacts, optical encodings, or magnetic particles. Theelectromechanical switch arrangement 110 according to this invention isprovided in addition to the dose dialled detector. If the processor 24,using the dose dialled detector, detects that the dose is changing, itis important also to determine whether a dose is being dialled in (dosesetting), dialled out (dose correction) or delivered (dose dispense).This determination is not possible using the dose dialled detectoralone. Use of the electromechanical switch arrangement 110 allows thisdetermination to be made.

If the processor 24 determines that the numbers detected by the OCRreader 25 are increasing and also that the electromechanical switcharrangement 110 is being alternately opened and closed, it can bededuced that a dose is being dialled into the injection device 1. If theprocessor 24 determines that the numbers detected by the OCR reader 25are decreasing and also that the electromechanical switch arrangement110 is being alternately opened and closed, it can be deduced that adose is being dialled out of the injection device 1, without beingdelivered. If the processor 24 determines that the numbers detected bythe OCR reader 25 are decreasing and also that no connection is made inthe electromechanical switch arrangement 110, it can be deduced that adose is being delivered.

The electromechanical switch arrangement 110 may also be used toactivate and control additional switching functions. This functionalitywill now be described with reference to FIGS. 12a and 12b . FIG. 12ashows diagrammatically the arrangement of some components of theinjection device 1 and supplemental device 2 when no dose is dialledinto the injection device. The dose dialling sleeve 119 is in the zeroposition. A zero appears in the window 13. The window 13 is in view ofthe OCR reader 25 which, under control of the processor 24, determinesthat no dose is dialled in. The dose dialling sleeve 119 extends fromthe housing 10 of the injection device by a distance large enough toallow the protrusion 118 of the switching member 113 to contact thesurface of the sleeve 119. The injection device 1 may be configured suchthat this spacing cannot be reduced further by rotating the dosage knob12. The protrusion 118 of the switching member 113 engages with a trough116 while in this position. As a result the electromechanical switcharrangement 110 does not form a connection between the two contacts 112.Each trough 116 of the dose dialling sleeve 119 ends at the dosage knob12 end with an axial ramp 122.

The processor 24 may determine that, if the OCR reader 25 detects a zerovalue, or alternatively, a dose dialled detector as described abovedetects a zero position of the dose dialling sleeve 119, and theelectromechanical switch arrangement 110 has not formed a connection,that the injection device 1 is not currently being used. After apredetermined time delay, the processor 24 may put the supplementaldevice 2 into a sleep mode.

As previously described, the injection button 11 and dose diallingsleeve 119 are coupled to an internal clutch (not visible) whichdisconnects these parts from the dosage knob 12 when the injectionbutton 11 is depressed. The clutch is sprung so as to bias the injectionbutton 11 in an un-depressed position. During dose delivery, theinjection button 11 must be fully depressed before the clutch isdisengaged, allowing the dose to be delivered. Thus the injection button11 and dose dialling sleeve 119 are able to move axially relative to theother components of the injection device 1 by an amount corresponding tothe distance over which the clutch remains engaged.

FIG. 12b shows diagrammatically the arrangement of some components ofthe injection device 1 and supplemental device 2 when the injectionbutton 11 is depressed when no dose is dialled in to the injectiondevice. Both the injection button 11 and dose dialling sleeve 119 movein the direction of the arrow “B” when the injection button 11 isdepressed. The protrusion 118 ascends the axial ramp 122 causing theswitch 113 to rotate which causes an electrical connection to be madebetween the contacts 112 in the electromechanical switch arrangement110, i.e. the switch is closed. If the user releases the force on theinjection button 11, the bias of the clutch causes the injection button11 and dose dialling sleeve 119 to return to the position shown in FIG.12a , in which the switch is open. This arrangement allows otherfunctions of the supplemental device 2 to be controlled by theelectromechanical switch arrangement 110, via the injection button 11 ofthe injection device 1.

The electromechanical switch arrangement 110 can be used as a“dispense-end” switch. During dispensing, the protrusion 118 remains ina trough 116 of the dose dialling sleeve 119 such that the switch isopen. If the user continues to apply force to the injection button 11after all of the dose has been delivered, the protrusion 118 ascends theaxial ramp 122 and the switch 110 is closed. When the user releases theforce, the switch is opened again. The processor 24 detects this closingand opening of the switch and determines that the dose has been fullyadministered. The processor 24 may then control the supplemental device2 to enter a dispense-end mode and control the display 21 to show anappropriate screen.

If the supplemental device 2 is in a sleep mode, for example because ithas been determined that the injection device 1 is not being used, theelectromechanical switch arrangement 110 may be used as a “wake-up”switch. The processor 24 may be configured to monitor theelectromechanical switch arrangement 110 while in sleep mode. If theuser depresses the injection button 11, the switch is closed. Theprocessor detects this action and turns the supplemental device 2 on.The supplemental device 2 enters a default mode when switched on in thismanner. In the default mode the dose dialled detector may be activatedand ready and/or operable to detect a dose that has been dialled.

The electromechanical switch arrangement 110 can also be used as a“menu-select” switch. If the supplemental device 2 is on, but no dosehas been dialled in, the closing of the switch by depressing theinjection button 11 causes the processor 24 to cycle through the menuoptions of the supplemental device 2.

Integrating these additional switching functions with the injectionbutton 11 of the injection device 1 simplifies the use of thesupplemental device 2 for a user.

The switching member 113 is described above as rotationally mounted.However, it may instead move in another way within the electromechanicalswitch arrangement 110, for example by sliding vertically. The internalspring 114 may be disposed in the centre of the switching member to biasit towards the aperture in the main body 111. The compensation spring115 may alternatively be a coil spring or another type of biasing means.Instead of being located adjacent to the electromechanical switcharrangement 110, the compensation spring 115 may be located above theelectromechanical switch arrangement 110, for example in a cavitybetween the housing 20 of the supplemental device 2 and the main body111 of the electromechanical switch arrangement 110. The switch 110 isdescribed as being closed when the protrusion 118 ascends a crest of thecorrugated dialling sleeve 119 or when the protrusion ascends the axialramp 122 and open at all other times. However, the switch 110 mayalternatively be opened when the protrusion ascends a corrugation or theaxial ramp 122 and closed at all other times. Thus the processor maydetect either state (or sense) change in the switch 110 and interpretthis change as described above.

The invention claimed is:
 1. A supplemental device for attachment to an injection device, the supplemental device comprising: a housing; an electromechanical switch arrangement, the electromechanical switch arrangement comprising: a main body, wherein a lower part of the main body is concave in shape and matches a curvature of the injection device; and a switching member positioned at least partially within the main body, the switching member having a protrusion arranged to protrude through an aperture in the lower part of the main body so as to contact a surface of the injection device while the supplemental device is attached to the injection device; and a biasing member configured to bias at least a part of the main body of the electromechanical switch arrangement against the injection device while the supplemental device is attached to the injection device; wherein the part of the main body of the electromechanical switch arrangement biased against the injection device comprises the aperture in the lower part of the main body.
 2. A supplemental device according to claim 1, wherein the electromechanical switch arrangement is disposed in a recess in the housing.
 3. A supplemental device according to claim 1, wherein the biasing member comprises a torsion spring having a first end secured to the housing of the supplemental device and a second end secured to the main body of the electromechanical switch arrangement.
 4. A supplemental device according claim 1, wherein the electromechanical switch arrangement further comprises an internal biasing member configured to bias the switching member towards a protruding position in which the protrusion extends beyond the main body of the electromechanical switch arrangement.
 5. A supplemental device according to claim 1, wherein the part of the main body of the electromechanical switch arrangement which is biased against the injection device houses the switching member.
 6. A supplemental device according to claim 1, wherein the whole of the main body of the electromechanical switch arrangement is biased against the injection device.
 7. A supplemental device according to claim 1, wherein the electromechanical switch arrangement is configured to be biased against a moveable surface of the injection device while the supplemental device is attached to the injection device.
 8. A supplemental device according to claim 1, wherein the switching member is rotatably mounted within the main body.
 9. A supplemental device according to claim 1, wherein the supplemental device further comprises a processor arrangement configured to determine whether the electromechanical switch arrangement is open or closed.
 10. A supplemental device according to claim 1, wherein the supplemental device further comprises a dose dialled detector operable to detect a dose of medicament dialled into an attached injection device.
 11. A supplemental device according to claim 10, wherein the dose dialled detector comprises an image capture device and an optical character recognition system.
 12. A system comprising a supplemental device as claimed in claim 1 and an injection device. 